JPS5828527A - Flow-passage controller for intake port - Google Patents

Abstract

PURPOSE:To obtain at all times proper swirling flow and a high charging efficiency irrespective of the loading state of an engine by branching the main branched passage branched from the inlet passage part in a helical-type intake port into two branched passages and connecting them to the terminal part and the starting part of the swirl part respectively. CONSTITUTION:A helical-type intake port 6 consists of the inlet passage part A having a slightly curved axis line of a flow passage and the swirl part B formed around an intake valve, and installed in a cylinder head 3. In this case, a main branched passage 13 is branched from the vicinity of the inlet opening of the inlet passage A, and further branched to the first and the second branched passages 14 and 15. The inlet opening 16 of the main branched passage 13 is formed on the side wall surface 9 in the vicinity of the inlet opening of the inlet passage part A, and the exit openings 17 and 19 of the first and the second branched passages 14 and 15 are respectively formed in the swirl terminating part C and the swrirl starting part D respectively. A flow-passage controlling valve 22 in a cantilevered thin lear form is arranged in the branched part 20 of the both branched parts 14 and 15, and said valve 22 controls switching according to the loaded state of an engine.

Description

[Detailed description of the invention] The present invention relates to an intake/-) flow path control device.

Intake air that can generate a strong swirling flow in the combustion chamber - includes, in part, a volute formed on the intake valve foot and an inlet passage tangentially connected to this volute and extending almost straight. Toyoshi configured helical reduced intake? - is known. However, such helical Wi
When trying to generate a strong swirling flow in the combustion chamber of an engine using an air intake when the engine is operating at low speed and low load with a small amount of intake air, the shape of some of the air intakes becomes shaped with large flow resistance.
This causes a problem of reduced filling efficiency during high-speed, high-load operation of the engine with a large amount of intake air.On the other hand, the side wall surface of the spiral part of such a helical air intake is close to the outer edge of the intake valve body. Since the diameter is also formed to bulge outward, the spiral radius of the spiral part and the radius of the intake valve body are large. In some cases, it may not be possible to use some of these Heli-Cal intakes because they interfere with the cylinder's intake port or exhaust port. In such a case, the swirl radius of the swirl portion must be made smaller, but if the swirl radius tube is made smaller, it becomes difficult to generate a strong swirling flow tube inside the combustion chamber during low-speed, low-load operation of the engine.

SUMMARY OF THE INVENTION An object of the present invention is to provide an air intake system that can ensure high charging efficiency during high-speed, high-load operation of the engine, and can also generate a strong swirling flow within the combustion chamber when the amount of intake air in the engine is small.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 1 and FIG. 2, 1 is a cylinder block, 2 is a piston that reciprocates within the cylinder block 1,
3 is a cylinder head fixed on the cylinder block 1; 4 is a combustion chamber formed between the piston 2 and the cylinder; 5 is an intake valve; 6 is an intake port formed within the cylinder head; 7 is a combustion chamber formed between the piston 2 and the cylinder; The exhaust valves 8 and 8 respectively indicate exhaust valves, and although not shown in the drawings, an ignition plug is disposed within the combustion chamber 4.

As can be seen from Fig. 1, the intake part 6 has a helical shape, and the present invention will be explained below based on the helical type intake/-)6. The radius of the part is from large to small.

It refers to all intake ports that have a structure where a swirling flow is generated in the spiral part, including those that have a spiral flow.

Therefore, it is clear that the spiral portion includes a cylindrical shape around the intake valve axis.

Figures 3 and 4 show the helical air intake shown in Figure 2 - part 6.
The shape of is shown diagrammatically. As shown in FIG. 4, this helical intake port 6 has an inlet passage section A in which the flow path axis a is slightly curved, and a spiral section B formed between the valve stems of the intake valve 5. The inlet passage section A is tangentially connected to the spiral section B. As shown in FIGS. 3, 4, and 7, the upper side wall surface 9a of the IUI surface 9 on the side closer to the spiral axis of the inlet passage part M is formed as a downwardly oriented inclined surface,
The width of this inclined surface 9& becomes wider as it approaches the spiral @B, and the width of the inclined surface 9& becomes wider as it approaches the spiral @B.
As shown in the figure, the entire side wall surface 9 is formed into a downwardly oriented inclined surface 9a. The upper half of the side wall surface 9 is smoothly connected to the peripheral wall surface of the cylindrical protrusion 11 formed on the earthen wall surface of the intake valve guide 10 (FIG. 2), while the lower half of the side wall surface 9 The half is connected to the side wall surface 12 of the spiral portion B at the spiral end C of the spiral portion B.

On the other hand, as shown in FIGS. 1 to 5, the inlet passage section A
A main branch road 13 is branched from near the entrance opening of the main branch road 13, and this main branch road 13 is further branched into a first branch road 14 and a second branch road 15. The inlet opening 16 of the main branch path 13 is the inlet passage section A.
The outlet opening 17 of the first branch passage 14 is formed on the side wall surface 9 of the inlet passage section A in the vicinity of the inlet opening of the spiral section A, and the outlet opening 17 of the first branch passage 14 is formed on the side wall surface 12 of the spiral section B in the vicinity of the spiral section upper wall surface 18 of the spiral terminal section C. is formed. Further, the outlet opening 19 of the second branch passage 15 is connected to the inlet passage part A at the beginning of the spiral part B.
It is formed on the inclined side wall surface 9a of.

A cantilevered thin plate-shaped flow control valve 22 supported by a valve shaft 21 is provided in the branching portion 20 between the first branching passage 14 and the second branching passage 15.
is placed. As can be seen from FIGS. 4 and 5, this flow path control valve 22 fully opens the second branch path 15 when the first branch path 14 is fully closed, and fully opens the first branch path 14 at 9'. The second branch passage 15 is fully closed. The upper end of the valve shaft 21 protrudes upward from the cylinder 3 and the arm 23 is fixed to the protruding upper end of the valve shaft 21 as shown in FIG. .

The tip of this arm 23 is connected via a connecting rod 24 to a control port 32 fixed to a diaphragm 31 of a negative pressure diaphragm device 30 .

The negative pressure diaphragm device 30 includes a negative pressure chamber 33 and an atmospheric pressure chamber 34 separated by a diaphragm 31.
A compression spring 35 for pressing the diaphragm is inserted into the diaphragm 3. This negative pressure chamber 33 includes a negative pressure conduit 36 and an electromagnetic control valve 37.
It is connected to the negative pressure accumulator 29 via. The electromagnetic control valve 37 communicates with the valve chamber 38, the negative pressure accumulator 29 (-) 39, and the atmosphere (-) which communicates with the atmosphere.
40, negative pressure/-) 39 and atmosphere/-) 40, a valve body 41 that controls opening/closing, a movable plunger 42 connected to the valve body 41, and a solenoid r4 for movable granger suction.
3, and this solenoid 43 is connected to the output terminal of the electronic control unit 50. On the other hand, an intake pipe 44 is connected to the intake part 6, and a carburetor (not shown) is attached to this intake pipe 44.

The negative pressure accumulator 29 is connected to the intake pipe 44 through a check valve 45 that allows flow only from the negative pressure accumulator 29 to the intake pipe 44 . Check valve 4! S is intake pipe 44
The valve opens when the negative pressure in the intake pipe 44 becomes negative and the negative pressure in the accumulator 29 also becomes smaller, and the valve closes. Negative pressure in the pressure accumulator 29 is generated in the intake pipe 44 and is maintained at a large negative pressure. On the other hand, a negative pressure sensor 46 for detecting negative pressure in the intake pipe 44 is mounted on the intake pipe 44, and the negative pressure sensor 46 is connected to an input terminal of the electronic control unit 50. In addition, the valve shaft 21 of the flow path control valve 22
An f-tension meter 47 for detecting the opening area of the flow path control valve 22 with respect to the first branch path 14 is attached to the holder. This 4-tension meter 47 includes a slider 47 & which is connected to the valve shaft 21 and rotates together with the valve shaft 21, and a fixed resistor 47b.
The slider 471 is configured to be in contact with and slide on the fixed resistor 47b. Therefore, nine voltages are generated in the slider 47m in proportion to the opening area of the flow path control valve 22 with respect to the first branch path 1'4. This slider 47 & is electronically controlled any)
50 input terminals.

On the other hand, a rotation speed sensor 48 is connected to an input terminal of an electronic control unit 50 to detect the rotation speed of the engine crankshaft.

The electronic control unit 50 is a digital combination, microprocessor (MP) that performs various arithmetic processing.
U) 51, Random access memory.

(RAM) 52, read-only memory (ROM) 5 in which control programs, calculation constants, etc. are stored in advance.
3. The input port 54 and the output port 55 are connected to each other via a bidirectional path 56. Furthermore, a clock generator 57 is provided within the electronic control unit 50 to generate various clock signals.

As shown in FIG. 9, the input port 54 is connected to the negative pressure sensor 46 and ? Tensile strength and meter 47 are connected, and input port 54 is also connected.
A rotation speed sensor 48 is connected to the negative pressure sensor 46. The negative pressure sensor 46 generates an output voltage proportional to the negative pressure in the intake pipe 44, and this voltage is converted into a corresponding binary number in the mu D converter 5B. The binary number is read into the MPU 51 via the input/−) 54 and path 56. On the other hand, the -tensimeter 47 generates an output voltage proportional to the opening area of the flow path control valve 22 with respect to the first branch 14, and this voltage is converted into a corresponding binary number by the D converter 59. The base number is input/-) 54 and the MPU via path 56.
51. 9. The rotation speed sensor 48 generates a pulse every time the crankshaft rotates by a predetermined crank angle, and this pulse is transmitted to the input l-t 54 and the pass 56.
The output port 55 is provided to output data for operating the electromagnetic control valve 37.
5, binary data is written from the MPU 51 via a path 56. Each output terminal of the output port 55 is connected to a corresponding input terminal of the down counter 60. The down counter 60 is written from the MPU 51 and is 92
The down counter 60 is provided to convert the base number data into the corresponding time length, and this down counter 60 outputs/
-) A down-count of the data sent from the clock generator 55 is started by the clock signal of the clock generator 57, and when the count value reaches 0, the count is completed and a count completion signal is generated at the output terminal.

The reset input terminal 8 of the S-R flip-flop 61 is connected to the output terminal of the down counter 60, and the set input terminal S of the S-1 register flip-flop 61 is connected to the clock generator 5.
Connected to 7. S-R flip-flop f61 is black,
It is set simultaneously with the start of the cedar run count by the clock signal of the down counter 60, and is reset by the count completion signal of the down counter 60 when the down count is completed. Therefore, the output terminal Q of the sn flip-flop f61 is at a high level while the down count is being performed. to]
The output terminal Q of FlipFlo and Zoro 1 is the power amplification circuit 62.
It is connected to the electromagnetic control valve 37 via. Therefore, the solenoid 43 of the electromagnetic control valve 32 is energized while the down counter is being performed.

When the solenoid 43 of the electromagnetic control valve 37 is deenergized, the valve body 41 opens the atmosphere 1-) 40' and closes the negative pressure /-) 39, as shown in FIG. 9, so that the negative pressure diaphragm device The inside of the negative pressure chamber 33 of No. 30 is at atmospheric pressure. At this time, the diaphragm 31 is at the lower end position due to the spring force of the compression spring 35, so the flow path control valve 22 fully closes the first branch passage 14 and fully opens the second branch passage 15. On the other hand, when the solenoid 43 of the electromagnetic control valve 37 is energized, the valve body 41 closes the atmosphere/-) 40 and opens the negative pressure port 39, so there is no negative pressure inside the negative pressure chamber 33 of the negative pressure diaphragm device 3o. The pressure is released, and negative pressure inside the mullet 29 is applied. At this time, the diaphragm 31 moves upward against the compression spring 35, causing the flow path control valve 22 to rotate counterclockwise, thereby causing the flow path control valve 22 to fully open the first branch path 14. At the same time, the second branch path 15 is completely closed. As described above, the solenoid 43 of the electromagnetic control valve 37 is energized while the down count is being performed, that is, when the voltage appearing at the output terminal Q of the Pflode 61 is at a high level. Therefore, the valve body 41 of the electromagnetic control valve 37 is negative 8Eyj! The rate of time for opening port 39 and closing port 40 is proportional to the duty cycle of the pulses applied to solenoid 43. .

The longer the time period for which the valve body 41 opens the negative pressure port 40 and closes the atmospheric port 40, the greater the negative pressure in the negative pressure chamber 33 of the negative pressure diaphragm device 30 becomes.
The opening area of the flow path control valve 22 with respect to the branch path 14 becomes larger. Therefore, the flow path control valve 22 for the first degree branch path 14
It can be seen that the opening area becomes larger as the duty cycle of the pulse applied to the solenoid 43 becomes larger.

FIG. 12 shows a preferable relationship between the opening area of the flow path control valve 22 with respect to the first branch path 14, the engine speed N, and the intake pipe negative pressure P. In Fig. 12, the vertical axis shows the engine speed N (r, pm), and the horizontal axis shows the intake pipe negative pressure P (-
ms+)Ig). Also, with hatching, nine curves 8. The upper region of 14 indicates the fully open region of the first branch road 14, and the region below the nine-curved line S1 with octagons indicates the fully closed region of the first branch road 14, with only two representative curves shown. s Snow eBsB The equal opening area curve of the flow path control valve for the first branch path 14 is shown. In addition, in FIG. 12, the opening area of the IfM control valve for the first branch path 14 is S.
.

It gradually increases from 8Hr8B to S. The preferred relationship between the engine speed N and V, the intake pipe negative pressure P, and the opening area S of the flow path control valve with respect to the first branch path 14 shown in FIG. 12 is stored in advance in the ROM 53 in the form of a function or data table. has been done.

FIG. 10 shows a flow chart for viewing and explaining the operation of the flow path control device according to the present invention. In FIG. 10, Stella f70 indicates that flow path control is performed by time interruption. First, in step 71, the output signal of the rotation speed sensor 48 is input into the MPU 51 to calculate the engine rotation speed, and then in step 72, the output signal of the negative pressure sensor 46 is input into the MPU 51. Next, in step 73, the target opening area SS of the flow path control valve for the 11 branch passage 14 is calculated from the relationship shown in Figure 1E13 stored in the ROM 53 based on the calculated 9 engine rotational speed N and the negative pressure P. In '741C, the output signal of the I-tensile meter 47 is input into the MPU 51 to determine the current opening area S of the flow path control valve for the first branch path 14.
Calculate. Next, in the step and guar 5, it is determined whether the target opening area SS is larger than the current opening area S. If it is determined in step 75 that the target opening area SS is larger than the current opening area S, step f76
At step 7, a constant value MU is added to the pulse width PL of the pulse to be applied to the solenoid 43 of the electromagnetic control valve 37, and this addition result is set as PL and the process proceeds to Step 7. On the other hand, Ste.
If it is determined in shift 5 that the target aperture area SS is not larger than the current aperture area S, the process proceeds to step 78, and in step 78, the eye S aperture area SS is determined to be smaller than the current aperture area S. It is determined whether or not. Step 7
When it is determined in step 8 that the target aperture area SS is smaller than the current aperture area S by υ, a constant value A is subtracted from the pulse width PL in step 79, and the subtraction result is used as PL, and the process proceeds to step 77. On the other hand, if it is determined in step 78 that the target opening area SS is not smaller than the current opening area 8, the process proceeds to step 77. In step 77, the binary drive data representing the /4 lus width PL thus obtained is written to the output port 55, and this output ? -G5
The energization control of the solenoid 43 of the electromagnetic control valve 37 is performed based on the drive data written in the control valve 5.

FIG. 11 shows a pulse applied to solenoid 43 of electromagnetic control valve 37, and while this pulse is occurring, solenoid 43 is energized. As described above, when the current opening area S of the flow path control valve for the first branch passage 14 is smaller than the target opening area SS, the nodules are adjusted until the opening area reaches the target opening area SS, as shown in FIG. The width is sequentially increased by a constant width. Therefore solenoid 4
The duty cycle of the telus applied to the negative pressure chamber 3 of the negative pressure diaphragm device 30 increases gradually.
The negative pressure inside the flow path control valve 2 gradually increases.
2 rotates to reach the target opening area SS. As can be seen from Fig. 13, the output voltage of the S-R flip-flop 7'61 remains at a low level continuously during low-speed engine operation with low load, low-speed operation with high engine load, and high-speed operation with low engine load. The solenoid 43 is deenergized and turned on, and the flow path control valve 22 continues to fully open the second branch path 15 and the first branch path 15.
Branch road 14 will remain closed. On the other hand, during engine high-speed, high-load operation, the output voltage of the S-R flip full 2 zoro 1 continues to be at a high level, and the solenoid 43 continues to be energized, thus causing the flow path control valve 22 to switch to the first branch. The passage 14 is kept fully open, and the second branch passage 15 is kept fully closed.

As described above, when the engine is operating at low load and low speed with a small amount of intake air, when the engine is operating at high load and low speed, and when the engine is operating at low load and high speed, the flow path control valve 22 fully closes the first branch passage 14 and closes the second branch passage 15. fully open.

At this time, part of the air-fuel mixture sent into the inlet passage A flows into the main branch passage 13, and the remaining air-fuel mixture flows into the inlet passage A.
Flows into the spiral part B from the inside of the spiral part B, and generates a swirling flow inside the spiral part B. On the other hand, the air-fuel mixture that has flowed into the main branch passage 13 flows out from the outlet opening 19 into the swirl starting part through the second branch passage 15, and is caused by the air-fuel mixture flowing out from the outlet opening 19 into the swirl part B.
The swirling flow generated within is intensified. The swirling flow thus increased in force flows into the combustion chamber 4 while swirling, and thus a strong swirling flow is generated within the combustion chamber 4. On the other hand, during engine high-speed, high-load operation with a large amount of intake air, the flow path control valve 22 fully opens the first branch passage 14 and fully closes the second branch passage 15. Therefore, at this time, a part of the air-fuel mixture injected into the inlet passage A is sent into the volute B through the main branch passage 13 and the first branch passage 14 with low flow resistance, which extend directly from t-p. The remaining air-fuel mixture flows from the inlet passage section A into the swirl section B. Outlet opening 1 of first branch path 14
The air-fuel mixture flowing out from the inlet passage 7 collides head-on with the air-mixture flow flowing along the upper wall surface 18 of the swirl portion from the inlet passage portion M, decelerating this air-mixture flow, thus weakening the swirling flow. In this manner, during high-speed, high-load operation of the engine, a large amount of air-fuel mixture is sent into the volute part B through the main branch passage 13 and the first branch passage 14, which have small flow resistance, and is further pumped into the volute part B from the inlet passage part M. Since the swirling flow caused by the catholic metal gas flowing into the tank is weakened, high filling efficiency can be ensured. In addition, by providing the inclined side wall ip9m in the inlet passage A, a part of the air-fuel mixture sent into the inlet passage A is given a downward force, and as a result, this air-fuel mixture flows through the inlet passage without swirling. A
C) The inflow resistance becomes small because the inflow flows into the spiral part B along the lower wall surface, thus making it possible to further improve the filling efficiency during high-speed, high-load operation.

On the other hand, in the area between curve 81 and curve l1lSo in FIG. 12, curves S1 to 8. As the intake air amount increases, as the intake air amount increases, the first
The opening area of the flow path control valve 22 with respect to the branch path 14 gradually increases. When the amount of intake air is small, it is necessary to generate strong turbulence within the combustion chamber 4 in order to ensure stable combustion, but as the amount of intake air increases, the naturally occurring turbulence becomes stronger, and the swirling flow is more likely to occur. It is necessary to suppress forced turbulence such as this, and it is also necessary to prevent a decrease in charging efficiency that causes a decrease in output as the amount of intake air increases. Therefore, as the amount of intake air increases, the opening area of the first branch passage 14 is gradually increased and the opening area of the second branch passage 15 is gradually decreased, thereby suppressing the generation of swirling flow and reducing the filling efficiency. In this way, it is possible to ensure an optimal swirl flow according to the amount of intake air and high filling efficiency.

As described above, according to the present invention, a strong swirling flow can be generated in the combustion chamber when the engine is operated at low speed and low load, when the engine is operated at high speed with low load, and when the engine is operated at high load and low speed, so that stable combustion can be ensured. At the same time, it is possible to suppress the occurrence of knocking, especially when the engine is operated at high load and low speed.

When the engine is operated at high speed and under high load, high charging efficiency can be ensured while suppressing the occurrence of swirling flow, so high output can be obtained. Furthermore, when the engine is operated at medium load and medium speed, it is possible to obtain an optimal swirling flow that is weakened as the amount of intake air increases and high charging efficiency.

[Brief explanation of the drawing]

Fig. 1 is a plan view of an internal combustion engine according to the present invention, and Fig. 2 is a plan view of an internal combustion engine according to the present invention.
Figure 3 is a perspective view showing the shape of the helical intake /-), Figure 4 is the plan view of Figure 3, and Figure 5 is the helical type of Figure 4. ! ! ! ! 6 is a cross-sectional view taken along the line ■-■ in FIG. 4, FIG. 7 is a cross-sectional view taken along the line ■-■ in FIG. 4, and FIG. The figure is a sectional view taken along the line ■-■ in Figure 4, Figure 9 is an overall view of the flow path control device, Figure 10 is a flowchart for explaining the operation of the flow path control device, and Figure 11 is a diagram showing the pulse applied to the solenoid of the solenoid control valve, the 12th
The figure shows the opening area of the slide valve. 5... Intake valve, 6... Intake/-), 13... Main branch path, 14... First branch path, 15... WJ2 branch path, 22... Flow path control valve, 30... Negative pressure diaphragm device, 37... Solenoid control valve, 50... Electronic control unit y). Patent applicant To1 Yu Jidosha Kogyo Co., Ltd. Patent application representative Patent attorney Akira Aoki Patent attorney Kazuyuki Nishidate Patent attorney Yoshi 1) Tadashi Patent attorney Akira Yamaguchi 1st 3rd session

Claims (1)

[Claims] Intake configured by a spiral formed in the intake valve leg and an inlet passage connected tangentially to the spiral and extending substantially straight - in part branched off from the inlet passage The main branching path is further branched into a first branching path and a second branching path, the first branching path is connected to the spiral end of the spiral portion, and the second branching path is connected to the spiral starting portion, A flow path control device for an intake date, in which a flow path control valve for controlling the amount of air flowing into the first branch path and the second branch path is provided at a branch portion of a first branch path and a second branch path.